So I had looked at that and quickly dismissed it because this is a fairly fresh/focused server and we really don't have jars anywhere else on the system. This was under the assumption that all of the Jars ReadyAPI has in their /lib folder work nicely together however that doesn't seem to be the case...
After removing mailapi-1.4.3.jar from ReadyAPI.../lib my tests now automagically work. I'm hesitant to call this a solution and am unsure why this is an issue on only ubuntu and not windows as well seeing as how the jar lives on both systems.
